Hum... thank you for these investigations... Please let us know your mods and the results !I have studied the circuit board a little bit. Nothing special, standard Schoeps CMC5 from 1973. But the component selection is nasty. JFET is MMBF5486, the output transistors are BC860C. All of them noisy as hell..
The oscillator circuits do not have the same frequency, they are shifted by about 23kHz. And now the first problem: After a while the beat frequency gets smaller and smaller. I saw 19kHz in the spectrum with nearly 1mV level! Maybe most of us do not detect this, but my grandchildren would...
Time to take the solder iron
That's incredible because even after a 2 hours recording I didn't notice any change in the sound : will investigate on my own too...
Regards
